WO2023185548A1 - 一种改性磷酸锰铁锂正极材料及其制备方法和应用 - Google Patents

一种改性磷酸锰铁锂正极材料及其制备方法和应用 Download PDF

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WO2023185548A1
WO2023185548A1 PCT/CN2023/082780 CN2023082780W WO2023185548A1 WO 2023185548 A1 WO2023185548 A1 WO 2023185548A1 CN 2023082780 W CN2023082780 W CN 2023082780W WO 2023185548 A1 WO2023185548 A1 WO 2023185548A1
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lithium iron
optionally
preparation
solution
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PCT/CN2023/082780
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French (fr)
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温圣耀
张�林
苑丁丁
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湖北亿纬动力有限公司
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    • C—CHEMISTRY; METALLURGY
    • C01—INORGANIC CHEMISTRY
    • C01B—NON-METALLIC ELEMENTS; COMPOUNDS THEREOF; METALLOIDS OR COMPOUNDS THEREOF NOT COVERED BY SUBCLASS C01C
    • C01B25/00—Phosphorus; Compounds thereof
    • C01B25/16—Oxyacids of phosphorus; Salts thereof
    • C01B25/26—Phosphates
    • C01B25/45—Phosphates containing plural metal, or metal and ammonium
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M10/00—Secondary cells; Manufacture thereof
    • H01M10/05—Accumulators with non-aqueous electrolyte
    • H01M10/052—Li-accumulators
    • H01M10/0525—Rocking-chair batteries, i.e. batteries with lithium insertion or intercalation in both electrodes; Lithium-ion batteries
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M4/00—Electrodes
    • H01M4/02—Electrodes composed of, or comprising, active material
    • H01M4/13—Electrodes for accumulators with non-aqueous electrolyte, e.g. for lithium-accumulators; Processes of manufacture thereof
    • H01M4/136—Electrodes based on inorganic compounds other than oxides or hydroxides, e.g. sulfides, selenides, tellurides, halogenides or LiCoFy
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M4/00—Electrodes
    • H01M4/02—Electrodes composed of, or comprising, active material
    • H01M4/36—Selection of substances as active materials, active masses, active liquids
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M4/00—Electrodes
    • H01M4/02—Electrodes composed of, or comprising, active material
    • H01M4/36—Selection of substances as active materials, active masses, active liquids
    • H01M4/58—Selection of substances as active materials, active masses, active liquids of inorganic compounds other than oxides or hydroxides, e.g. sulfides, selenides, tellurides, halogenides or LiCoFy; of polyanionic structures, e.g. phosphates, silicates or borates
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M4/00—Electrodes
    • H01M4/02—Electrodes composed of, or comprising, active material
    • H01M4/62—Selection of inactive substances as ingredients for active masses, e.g. binders, fillers
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
    • Y02E60/00—Enabling technologies; Technologies with a potential or indirect contribution to GHG emissions mitigation
    • Y02E60/10—Energy storage using batteries

Definitions

  • This application belongs to the field of lithium-ion batteries and relates to a modified lithium iron manganese phosphate cathode material and its preparation method and application.
  • LFP lithium iron phosphate
  • ternary materials the main cathode materials for lithium-ion power batteries.
  • LFP has gradually become the preferred choice for energy storage and power battery companies due to its advantages such as high cost performance, high safety and small resource bottlenecks.
  • it has the problem of low energy density, which has become a key factor restricting the large-scale application of lithium iron phosphate. .
  • Lithium iron manganese phosphate is a cathode material obtained by adding manganese element to LFP.
  • the doping of manganese can make LMFP have a higher voltage platform (4.1V vs 3.4V), increasing the energy density of the battery. About 15%, it is a cathode material with great application prospects.
  • the current LMFP cathode material is still in the early stages of industrialization. The main reason is that LMFP has low electronic conductivity and ion diffusion rate, low first Coulombic efficiency, and poor cycle performance, which seriously affects its commercial implementation. Therefore, how to improve the electronic conductivity, ion transport rate and cycle stability of LMFP materials is the current key technology. At present, the effective way to solve this technical problem is to lattice dope and coat the LMFP material.
  • CN109244424A discloses a method for preparing an alumina-coated manganese-doped lithium iron phosphate cathode material.
  • the method uses hydrothermal reaction to obtain a manganese-doped lithium iron phosphate cathode material, and then sequentially adds the manganese-doped lithium iron phosphate cathode material to the powder.
  • the organic solution ethanol and aluminum sulfate solution are stirred and mixed, and then calcined at high temperature to obtain an alumina-coated manganese-doped lithium iron phosphate cathode material.
  • the alumina-coated manganese-doped lithium iron phosphate cathode material prepared by this method can effectively improve the conductivity and charge and discharge capacity of the material.
  • the capacity retention rate of the cathode material prepared by this method is only 94.5% after 500 times, which cannot meet the needs of power batteries. need.
  • CN113942990A discloses a method of preparing carbon-coated and ion-doped lithium iron manganese phosphate cathode material using coprecipitation reaction. This method overcomes the problems of uneven element distribution, low compaction density and low specific capacity of lithium iron manganese phosphate cathode material. However, the ionic conductivity of the material is not high and the cycle stability is poor. After the assembled buckle is cycled for 80 cycles at a rate of 1C, the capacity decays to 95.8%.
  • This application provides a preparation method of an LMFP cathode material that has been dual-modified by ion doping and fast ion conductor coating. , synergistically improve the rate performance and cycle performance of LMFP electrode materials.
  • embodiments of the present application provide a method for preparing a modified lithium iron manganese phosphate cathode material.
  • the preparation method includes the following steps:
  • the M source includes any one or a combination of at least two of the salts or oxides of vanadium, aluminum, zirconium, titanium, and magnesium.
  • the modified lithium iron manganese phosphate cathode material prepared by the method described in the embodiments of this application is a preparation method for the LMFP cathode material dual modification modified by ion doping and fast ion conductor coating.
  • the doped iron manganese precursor is synthesized. It can make the two materials of manganese and iron evenly mixed, prevent the enrichment and phase separation of ferromanganese from affecting the performance of electrical properties, and allow doping elements to enter the metal sites to improve the conductivity of the host material.
  • the ferromanganese precursor is first synthesized, and then doped with metal and mixed with a lithium source to synthesize LMFP. Finally, the fast ion conductor is coated on the surface of the LMFP through ball milling and sintering to obtain a double-modified LMFP with ion doping and fast ion conductor coating.
  • the prepared lithium oxide coating layer has good uniformity, consistency and conductivity. The preparation process of this method is simple and controllable, and is easy for large-scale industrial production.
  • the manganese source in step (1) includes any one or a combination of at least two of manganese sulfate, manganese carbonate, manganese nitrate, manganese acetate or manganese oxalate.
  • the iron source includes iron phosphate and/or iron powder.
  • the doping metal source includes magnesium, calcium, aluminum, cobalt, nickel, zinc, molybdenum, titanium, tungsten, alum, chromium, antimony, neodymium, niobium oxides, hydroxides, chlorine Any one or a combination of at least two of compounds, sulfates, nitrates, acetates or acetates.
  • the solvent includes deionized water.
  • the phosphorus source in step (2) includes phosphoric acid and/or ammonium dihydrogen phosphate.
  • the ammonia source includes any one or a combination of at least two of ammonia, ammonium monohydrogen phosphate, ammonium dihydrogen phosphate, ammonium sulfate or urea.
  • the lithium source in step (3) includes lithium carbonate and/or lithium dihydrogen phosphate.
  • the temperature of the heat treatment is 300-500°C, such as: 300°C, 350°C, 400°C, 450°C or 500°C, etc.
  • the heat treatment time is 3-10 hours, such as: 3 hours, 5 hours, 6 hours, 8 hours, 10 hours, etc.
  • the Mn/Fe ratio is 0.9-0.1, for example: 0.9, 0.8, 0.7, 0.6, 0.5, 0.4, 0.3, 0.2, 0.1, etc., preferably 0.6.
  • the mass ratio of the fast ion conductor and lithium iron manganese phosphate powder in step (4) is 0.1-10:100, for example: 0.1:100, 0.5:100, 1:100, 2:100, 5:100 or 10:100, etc., preferably 1-5:100.
  • the grinding method includes ball milling.
  • the speed of the ball mill is 500-1500r/min, such as: 500r/min, 800r/min, 1000r/min, 1200r/min or 1500r/min, etc.
  • the ball milling time is 0.5-5h, for example: 0.5h, 1h, 2h, 3h or 5h, etc.
  • the temperature of the sintering treatment in step (4) is 200-600°C, for example: 200°C, 300°C, 400°C, 500°C or 600°C, etc.
  • the sintering treatment time is 2-15h, for example: 2h, 5h, 8h, 10h or 15h, etc.
  • embodiments of the present application provide a modified lithium iron manganese phosphate cathode material, which is prepared by the method described in the first aspect.
  • the modified lithium iron manganese phosphate cathode material includes an ion-doped core and a fast ion conductor coating layer disposed on the surface of the ion-doped core.
  • the surface of LMFP is coated with a fast ion conductor.
  • the coating layer can be used as a protective layer to inhibit the dissolution of manganese and inhibit the erosion of the cathode material by HF, thereby improving the cycle stability of the material; on the other hand, it can also As a lithium fast ion conductor, it enhances the ionic conductivity of the material, reduces the charge transfer resistance of the battery during the charge and discharge process, effectively improves the interface impedance and charge between the electrolyte and the cathode material, and improves the rate performance; in addition, it can also supplement the formation
  • the lithium ions consumed by the SEI film increase the first Coulombic efficiency of the material.
  • the thickness of the fast ion conductor coating layer is 10-50 nm, for example: 10 nm, 20 nm, 30 nm, 40 nm or 50 nm, etc., preferably 20-30 nm.
  • the median particle size D50 of the modified lithium iron manganese phosphate cathode material is 0.5-5 ⁇ m, such as: 0.5 ⁇ m, 1 ⁇ m, 2 ⁇ m, 3 ⁇ m, 4 ⁇ m or 5 ⁇ m, etc.
  • embodiments of the present application provide a cathode electrode sheet, which contains the modified lithium iron manganese phosphate cathode material as described in the second aspect.
  • embodiments of the present application provide a lithium-ion battery, which includes the positive electrode sheet as described in the third aspect.
  • the preparation method described in this application first synthesizes the doped ferromanganese precursor, which can not only mix the two materials of manganese and ferromanganese evenly, but also prevent the enrichment and phase separation of ferromanganese from affecting the performance of electrical properties, and allow doping elements to enter Metal sites improve the conductivity of the host material.
  • the surface of the LMFP of this application is coated with a fast ion conductor.
  • the coating layer can be used as a protective layer to inhibit the dissolution of manganese and inhibit the erosion of the cathode material by HF, thereby improving the cycle stability of the material; on the other hand, it can also As a lithium fast ion conductor, it enhances the ionic conductivity of the material, reduces the charge transfer resistance of the battery during the charge and discharge process, effectively improves the interface impedance and charge between the electrolyte and the cathode material, and increases the efficiency performance; in addition, it can replenish the lithium ions consumed in forming the SEI film and improve the first Coulombic efficiency of the material.
  • This embodiment provides a modified lithium iron manganese phosphate cathode material.
  • the preparation method of the modified lithium iron manganese phosphate cathode material includes the following steps:
  • the thickness of the coating layer of the modified lithium iron manganese phosphate cathode material is 15 nm, and the median particle size D50 of the modified lithium iron manganese phosphate cathode material is 1.2 ⁇ m.
  • This embodiment provides a modified lithium iron manganese phosphate cathode material.
  • the preparation method of the modified lithium iron manganese phosphate cathode material includes the following steps:
  • the thickness of the coating layer of the modified lithium iron manganese phosphate cathode material is 18 nm, and the median particle size D50 of the modified lithium iron manganese phosphate cathode material is 1.5 ⁇ m.
  • Example 1 The only difference between this embodiment and Example 1 is that the mass ratio of the fast ion conductor and lithium iron manganese phosphate is controlled to be 0.5:100, and the thickness of the coating layer of the modified lithium iron manganese phosphate cathode material is 5 nm. Other conditions are the same as The parameters are exactly the same as those in Example 1.
  • Example 1 The only difference between this embodiment and Example 1 is that the mass ratio of the fast ion conductor and lithium iron manganese phosphate is controlled to 8:100, and the thickness of the coating layer of the modified lithium iron manganese phosphate cathode material is 60 nm. Other conditions The parameters are exactly the same as those in Example 1.
  • Example 1 The only difference between this comparative example and Example 1 is that the fast ion conductor is not coated, and other conditions and parameters are exactly the same as Example 1.
  • Example 1 The only difference between this comparative example and Example 1 is that the fast ion conductor is replaced by alumina, and other conditions and parameters are exactly the same as Example 1.
  • Example 1 The only difference between this comparative example and Example 1 is that the manganese source, iron source, phosphorus source and doping metal source are directly mixed to form a precursor.
  • the other conditions and parameters are exactly the same as Example 1.
  • the modified lithium iron manganese phosphate cathode material obtained in Examples 1-4 and Comparative Examples 1-3 was used as the cathode material.
  • the negative electrode material was graphitic carbon material, with PE/PP polymer material as the separator, and was wound or laminated. Assemble into a roll core, encapsulate it in an aluminum shell or aluminum plastic film, inject organic solvents such as EC/EMC and lithium ion electrolyte composed of LiPF 6 , assemble into a soft-pack lithium ion battery, and conduct electrical performance tests on the battery.
  • the test results are shown in Table 1:
  • Example 1 it can be seen from the comparison between Example 1 and Example 3-4 that during the preparation process of the modified lithium iron manganese phosphate cathode material described in this application, the amount of fast ion conductor added will affect the quality of the fast ion conductor coating layer of the cathode material.
  • the thickness affects the performance of the modified lithium iron manganese phosphate cathode material.
  • the performance of the modified lithium iron manganese phosphate cathode material can be obtained. If the addition amount of fast ion conductor is too large, the active ingredients will be less and the gram capacity will be low. If the addition amount of fast ion conductor is too small, the effect will not be obvious.
  • the present application coats the surface of LMFP with a fast ion conductor.
  • the coating layer can be used as a protective layer to inhibit the dissolution of manganese and inhibit the erosion of the cathode material by HF, thereby Improve the cycle stability of the material; on the other hand, it can also be used as a lithium fast ion conductor to enhance the ionic conductivity of the material, reduce the charge transfer resistance of the battery during charge and discharge, and effectively improve the interface impedance and charge between the electrolyte and the cathode material. Improve rate performance; in addition, it can also replenish the lithium ions consumed in forming the SEI film and improve the first Coulombic efficiency of the material.
  • Example 1 Comparative Example 3
  • the present application first synthesizes a doped ferromanganese precursor, which can not only mix the two ferromanganese materials evenly, but also prevent the enrichment and phase separation of ferromanganese from affecting the performance of electrical properties. to mix Miscellaneous elements enter the metal site and improve the conductivity of the host material.

Abstract

本申请提供了一种改性磷酸锰铁锂正极材料及其制备方法和应用，所述制备方法包括以下步骤：(1)将锰源、铁源和掺杂金属源与溶剂混合得到溶液A；(2)将磷源、氨源和过氧化氢加入溶液A，得到溶液B；(3)将溶液B和锂源混合进行研磨，热处理得到磷酸锰铁锂粉料；(4)将锂源和M源与溶剂混合，得到快离子导体溶液，将所述快离子导体溶液和磷酸锰铁锂粉料混合进行研磨，经烧结处理得到所述改性磷酸锰铁锂正极材料，本申请提供了一种离子掺杂和快离子导体包覆双重修饰改性处理的LMFP正极材料的制备方法，协同提高LMFP电极材料的倍率性能和循环性能。

Description

一种改性磷酸锰铁锂正极材料及其制备方法和应用
本申请要求在2022年12月14日提交中国专利局、申请号为202211611236.X的中国专利申请的优先权，以上申请的全部内容通过引用结合在本申请中。
技术领域
本申请属于锂离子电池领域，涉及一种改性磷酸锰铁锂正极材料及其制备方法和应用。
背景技术
近年来“碳中和”已经受到全世界各国重点关注，新能源汽车蓬勃发展，带动了锂离子动力电池需求的迅速增长。目前，锂离子动力电池的正极材料主要磷酸铁锂(LFP)和三元材料。其中，LFP凭借高性价比、高安全性以及资源瓶颈小等优势，逐渐成为储能和动力电池企业的优先选择，然而其存在能量密度低的问题，这成为制约磷酸铁锂大规模应用的关键因素。
磷酸锰铁锂(LMFP)是在LFP的基础上添加锰元素后获得的一种正极材料，锰的掺杂可使LMFP具有更高的电压平台(4.1V vs 3.4V)，电池的能量密度提升15％左右，是一种具有极大应用前景的正极材料。当前LMFP正极材料还处于产业化初期，其主要原因是LMFP电子导电率和离子扩散速率较低，首次库伦效率低，循环性能差，这严重影响其商业落地。因此，如何提高LMFP材料的电子导电、离子传输速率以及循环稳定性是当前的技术关键。目前，解决该技术问题有效的办法就是对LMFP材料进行晶格掺杂和包覆处理。
CN109244424A公开了一种氧化铝包覆锰掺杂磷酸铁锂正极材料的制备方法，该方法采用水热反应获得锰掺杂磷酸铁锂正极材料，然后在此粉料中依次加入 有机溶液乙醇、硫酸铝溶液搅拌混合，高温煅烧获得氧化铝包覆锰掺杂磷酸铁锂正极材料。该方法制备的氧化铝包覆锰掺杂磷酸铁锂正极材料可有效提高材料的导电性和充放电容量，但该方法制备的正极材料500次后容量保持率仅为94.5％，无法满足动力电池需求。
CN113942990A公开了一种采用共沉淀反应制备碳包覆和离子掺杂的磷酸锰铁锂正极材料，该方法克服了磷酸锰铁锂正极材料元素分布不均匀、压实密度低、比容量不高的问题，但材料的离子导电性不高，循环稳定性较差，其组装成的扣电在1C倍率下循环80周后，容量衰减至95.8％。
发明内容
以下是对本文详细描述的主题的概述。本概述并非是为了限制权利要求的保护范围。
本申请的目的在于提供一种改性磷酸锰铁锂正极材料及其制备方法和应用，本申请提供了一种离子掺杂和快离子导体包覆双重修饰改性处理的LMFP正极材料的制备方法，协同提高LMFP电极材料的倍率性能和循环性能。
为达到此申请目的，本申请采用以下技术方案：
第一方面，本申请实施例提供了一种改性磷酸锰铁锂正极材料的制备方法，所述制备方法包括以下步骤：
(1)将锰源、铁源和掺杂金属源与溶剂混合得到溶液A；
(2)将磷源、氨源和过氧化氢加入溶液A，得到溶液B；
(3)将溶液B和锂源混合进行研磨，热处理得到磷酸锰铁锂粉料；
(4)将锂源和M源与溶剂混合，得到快离子导体溶液，将所述快离子导体溶液和磷酸锰铁锂粉料混合进行研磨，经烧结处理得到所述改性磷酸锰铁锂正 极材料；
其中，M源包括钒、铝、锆、钛、镁的盐或氧化物中的任意一种或至少两种的组合。
本申请实施例所述方法制得改性磷酸锰铁锂正极材料为离子掺杂和快离子导体包覆双重修饰改性的LMFP正极材料的制备方法，首先合成掺杂的锰铁前驱体，既可以使锰铁两种物混合均匀，防止锰铁富集分相影响电性能的发挥，有可使掺杂元素进入金属位点，提高主体材料导电性。
本申请实施例先合成锰铁前驱体，再掺杂金属、混合锂源合成LMFP，最后将快离子导体通过球磨包覆在LMFP表面，烧结处理得到离子掺杂和快离子导体包覆双重修饰的LMFP正极材料。制备的氧化锂包覆层具有良好的均匀性、一致性与导电性，该方法制备过程简单可控，易于大规模工业化生产。
在一个实施例中，步骤(1)所述锰源包括硫酸锰、碳酸锰、硝酸锰、醋酸锰或草酸锰中的任意一种或至少两种的组合。
在一个实施例中，所述铁源包括磷酸铁和/或铁粉。
在一个实施例中，所述掺杂金属源包括镁、钙、铝、钴、镍、锌、钼、钛、钨、矾、铬、锑、钕、铌元素的氧化物、氢氧化物、氯化物、硫酸盐、硝酸盐、乙酸盐或醋酸盐中的任意一种或至少两种的组合。
在一个实施例中，所述溶剂包括去离子水。
在一个实施例中，步骤(2)所述磷源包括磷酸和/或磷酸二氢铵。
在一个实施例中，所述氨源包括氨水、磷酸一氢铵、磷酸二氢铵、硫酸铵或尿素中的中的任意一种或至少两种的组合。
在一个实施例中，步骤(3)所述锂源包括碳酸锂和/或磷酸二氢锂。
在一个实施例中，所述热处理的温度为300-500℃，例如：300℃、350℃、400℃、450℃或500℃等。
在一个实施例中，所述热处理的时间为3-10h，例如：3h、5h、6h、8h或10h等。
在一个实施例中，所述磷酸锰铁锂中，Mn/Fe比例为0.9-0.1，例如：0.9、0.8、0.7、0.6、0.5、0.4、0.3、0.2、0.1等，优选为0.6。
在一个实施例中，步骤(4)所述快离子导体和磷酸锰铁锂粉料的质量比为0.1-10:100，例如：0.1:100、0.5:100、1:100、2:100、5:100或10:100等，优选为1-5:100。
在一个实施例中，所述研磨的方式包括球磨。
在一个实施例中，所述球磨的速度为500-1500r/min，例如：500r/min、800r/min、1000r/min、1200r/min或1500r/min等。
在一个实施例中，所述球磨的时间为0.5-5h，例如：0.5h、1h、2h、3h或5h等。
在一个实施例中，步骤(4)所述烧结处理的温度为200-600℃，例如：200℃、300℃、400℃、500℃或600℃等。
在一个实施例中，所述烧结处理的时间为2-15h，例如：2h、5h、8h、10h或15h等。
第二方面，本申请实施例提供了一种改性磷酸锰铁锂正极材料，所述改性磷酸锰铁锂正极材料通过如第一方面所述方法制得。
在一个实施例中，所述改性磷酸锰铁锂正极材料包括离子掺杂内核和设置于所述离子掺杂内核表面的快离子导体包覆层。
本申请实施例在LMFP表面包覆快离子导体，一方面该包覆层可以作为保护层，抑制锰的溶解，抑制HF对正极材料的侵蚀，从而提高材料的循环稳定性；另一方面也可以作为锂快离子导体，增强材料的离子导电性，降低电池在充放电过程中的电荷转移电阻，有效改善电解液与正极材料的界面阻抗和电荷，提高倍率性能；除此之外还可补充形成SEI膜消耗的锂离子，提高材料的首次库伦效率。
在一个实施例中，所述快离子导体包覆层的厚度为10-50nm，例如：10nm、20nm、30nm、40nm或50nm等，优选为20-30nm。
在一个实施例中，所述改性磷酸锰铁锂正极材料的中值粒径D50为0.5-5μm，例如：0.5μm、1μm、2μm、3μm、4μm或5μm等。
第三方面，本申请实施例提供了一种正极极片，所述正极极片包含如第二方面所述的改性磷酸锰铁锂正极材料。
第四方面，本申请实施例提供了一种锂离子电池，所述锂离子电池包含如第三方面所述的正极极片。
相对于相关技术，本申请具有以下有益效果：
(1)本申请所述制备方法首先合成掺杂的锰铁前驱体，既可以使锰铁两种物混合均匀，防止锰铁富集分相影响电性能的发挥，有可使掺杂元素进入金属位点，提高主体材料导电性。
(2)本申请LMFP表面包覆快离子导体，一方面该包覆层可以作为保护层，抑制锰的溶解，抑制HF对正极材料的侵蚀，从而提高材料的循环稳定性；另一方面也可以作为锂快离子导体，增强材料的离子导电性，降低电池在充放电过程中的电荷转移电阻，有效改善电解液与正极材料的界面阻抗和电荷，提高倍 率性能；除此之外还可补充形成SEI膜消耗的锂离子，提高材料的首次库伦效率。
(3)本申请在LMFP材料表面包覆快离子导体虽然优点颇多，但快离子导体的主要作用仍为增强锂离子传导，加入过多，导致主成分减少，进而减少LMFP材料的克容量；加入过少，所起作用不明显。
在阅读并理解了详细描述后，可以明白其他方面。
具体实施方式
实施例1
本实施例提供了一种改性磷酸锰铁锂正极材料，所述改性磷酸锰铁锂正极材料的制备方法包括以下步骤：
(1)将碳酸锰、铁粉按照摩尔比Mn:Fe＝0.6:0.4和稀盐酸混合，加入硫酸锰和铁粉的总质量的1％的硫酸镍，得到溶液A；
(2)将按照摩尔比Mn:Fe:PO4为0.6:0.4:1将磷酸加入溶液A，再依次加入过氧化氢和氨水，得到溶液B；
(3)将溶液B和碳酸锂(Li:PO4＝1:0.95)混合进行研磨，300℃下热处理6h得到磷酸锰铁锂粉料，所述粉料的化学式为LiMn0.6Fe0.4PO4；
(4)将碳酸锂和氧化铌与去离子水混合，得到快离子导体浆料，将所述快离子导体浆料和磷酸锰铁锂粉料混合在600rpm下球磨2h，其中，快离子导体和磷酸锰铁锂粉料的质量为1:100，在氮气气氛、500℃下烧结3h，随后在氮气气氛中冷却至室温，得到所述改性磷酸锰铁锂正极材料；
所述改性磷酸锰铁锂正极材料的包覆层厚度为15nm，所述改性磷酸锰铁锂正极材料的中值粒径D50为1.2μm。
实施例2
本实施例提供了一种改性磷酸锰铁锂正极材料，所述改性磷酸锰铁锂正极材料的制备方法包括以下步骤：
(1)将碳酸锰、铁粉按照摩尔比Mn:Fe＝0.6:0.4和去离子水混合，加入硫酸锰和铁粉的总质量的1.2％的硫酸镁，得到溶液A；
(2)将按照摩尔比Mn:Fe:PO4为0.6:0.4:1将磷酸加入溶液A，再依次加入过氧化氢和氨水，得到溶液B；
(3)将溶液B和碳酸锂(Li:PO4＝1:0.95)混合进行研磨，400℃下热处理4h得到磷酸锰铁锂粉料，所述粉料的化学式为LiMn0.6Fe0.4PO4；
(4)将碳酸锂和氧化铌与去离子水混合，得到快离子导体溶液，将所述快离子导体溶液和磷酸锰铁锂粉料混合在700rpm下球磨2h，其中，快离子导体和磷酸锰铁锂粉料的质量为2:100，在氮气气氛、400℃下烧结5h，随后在氮气气氛中冷却至室温，得到所述改性磷酸锰铁锂正极材料；
所述改性磷酸锰铁锂正极材料的包覆层厚度为18nm，所述改性磷酸锰铁锂正极材料的中值粒径D50为1.5μm。
实施例3
本实施例与实施例1区别仅在于，控制加入快离子导体和磷酸锰铁锂的质量比为0.5:100，制得改性磷酸锰铁锂正极材料的包覆层厚度为5nm，其他条件与参数与实施例1完全相同。
实施例4
本实施例与实施例1区别仅在于，控制加入快离子导体和磷酸锰铁锂的质量比为8:100，制得改性磷酸锰铁锂正极材料的包覆层厚度为60nm，其他条件 与参数与实施例1完全相同。
对比例1
本对比例与实施例1区别仅在于，不包覆快离子导体，其他条件与参数与实施例1完全相同。
对比例2
本对比例与实施例1区别仅在于，将快离子导体换为氧化铝，其他条件与参数与实施例1完全相同。
对比例3
本对比例与实施例1区别仅在于，直接将锰源、铁源、磷源和掺杂金属源混合制成前驱体，其他条件与参数与实施例1完全相同。
性能测试：
以实施例1-4和对比例1-3得到的改性磷酸锰铁锂正极材料作为正极材料，负极材料选取石墨碳材料，搭配PE/PP高分子材料作为隔膜，采用卷绕或者叠片方式组装成卷芯，封装在铝壳或者铝塑膜中，并注入EC/EMC等有机溶剂和LiPF6组成的锂离子电解液，组装成软包锂离子电池，对所述电池进行电性能测试，测试结果如表1所示：
表1

由表1可以看出，由实施例1-2可得，掺杂金属元素及包覆快离子导体有利于提升材料库伦效率及倍率放电性能，同时改善循环保持率；但是快离子导体包覆量过多时，虽然有利于提升倍率性能，但首次库伦效率及循环反而降低。
由实施例1和实施例3-4对比可得，本申请所述改性磷酸锰铁锂正极材料的制备过程中，快离子导体的加入量会影响制得正极材料快离子导体包覆层的厚度，进而影响改性磷酸锰铁锂正极材料性能，将快离子导体和磷酸锰铁锂粉体的质量比控制在1-5％，制得改性磷酸锰铁锂正极材料的性能较好，若快离子导体的加入量过大，活性成分较少，克容量偏低，若快离子导体的加入量过小，效果不明显。
由实施例1和对比例1-2对比可得，本申请在LMFP表面包覆快离子导体，一方面该包覆层可以作为保护层，抑制锰的溶解，抑制HF对正极材料的侵蚀，从而提高材料的循环稳定性；另一方面也可以作为锂快离子导体，增强材料的离子导电性，降低电池在充放电过程中的电荷转移电阻，有效改善电解液与正极材料的界面阻抗和电荷，提高倍率性能；除此之外还可补充形成SEI膜消耗的锂离子，提高材料的首次库伦效率。
由实施例1和对比例3对比可得，本申请首先合成掺杂的锰铁前驱体，既可以使锰铁两种物混合均匀，防止锰铁富集分相影响电性能的发挥，有可使掺 杂元素进入金属位点，提高主体材料导电性。

Claims (9)

  1. 一种改性磷酸锰铁锂正极材料的制备方法，所述制备方法包括以下步骤：
    (1)将锰源、铁源和掺杂金属源与溶剂混合得到溶液A；
    (2)将磷源、氨源和过氧化氢加入溶液A，得到溶液B；
    (3)将溶液B和锂源混合进行研磨，热处理得到磷酸锰铁锂粉料；
    (4)将锂源和M源与溶剂混合，得到快离子导体溶液，将所述快离子导体溶液和磷酸锰铁锂粉料混合进行研磨，经烧结处理得到所述改性磷酸锰铁锂正极材料；
    其中，M源包括钒、铝、锆、钛的盐或氧化物中的任意一种或至少两种的组合。
  2. 如权利要求1所述的制备方法，其中，步骤(1)所述锰源包括硫酸锰、碳酸锰、硝酸锰、醋酸锰或草酸锰中的任意一种或至少两种的组合；
    可选地，所述铁源包括磷酸铁和/或铁粉；
    可选地，所述掺杂金属源包括镁、钙、铝、钴、镍、锌、钼、钛、钨、矾、铬、锑、钕、铌元素的氧化物、氢氧化物、氯化物、硫酸盐、硝酸盐、乙酸盐或醋酸盐中的任意一种或至少两种的组合；
    可选地，所述溶剂包括去离子水。
  3. 如权利要求1或2所述的制备方法，其中，步骤(2)所述磷源包括磷酸和/或磷酸二氢铵；
    可选地，所述氨源包括氨水、磷酸一氢铵、磷酸二氢铵、硫酸铵或尿素中的中的任意一种或至少两种的组合。
  4. 如权利要求1-3任一项所述的制备方法，其中，步骤(3)所述锂源包括碳酸锂和/或磷酸二氢锂；
    可选地，所述热处理的温度为300-500℃；
    可选地，所述热处理的时间为3-10h。
  5. 如权利要求1-4任一项所述的制备方法，其中，步骤(4)所述快离子导体和磷酸锰铁锂粉料的质量比为0.1-10:100，优选为1-5:100；
    可选地，所述研磨的方式包括球磨；
    可选地，所述球磨的速度为500-1500r/min；
    可选地，所述球磨的时间为0.5-5h。
  6. 如权利要求1-5任一项所述的制备方法，其中，步骤(4)所述烧结处理的温度为200-600℃；
    可选地，所述烧结处理的时间为2-15h。
  7. 一种改性磷酸锰铁锂正极材料，所述改性磷酸锰铁锂正极材料通过如权利要求1-6任一项所述方法制得。
  8. 如权利要求7所述的改性磷酸锰铁锂正极材料，其中，所述改性磷酸锰铁锂正极材料包括离子掺杂内核和设置于所述离子掺杂内核表面的快离子导体包覆层；
    可选地，所述快离子导体包覆层的厚度为10-50nm，优选为20-30nm；
    可选地，所述改性磷酸锰铁锂正极材料的中值粒径D50为0.5-5μm。
  9. 一种正极极片，所述正极极片包含如权利要求7或8所述的改性磷酸锰铁锂正极材料。
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Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2018006156A (ja) * 2016-07-01 2018-01-11 太平洋セメント株式会社 ポリアニオン系正極活物質及びその製造方法
CN109761210A (zh) * 2018-12-13 2019-05-17 天津力神电池股份有限公司 磷酸锰铁锂的制备方法及其包覆三元材料的方法
CN110890541A (zh) * 2019-11-21 2020-03-17 国联汽车动力电池研究院有限责任公司 一种表面改性富锂锰基正极材料的制备方法和锂离子电池
CN113659134A (zh) * 2021-07-09 2021-11-16 江苏乐能电池股份有限公司 一种使用共结晶法制备纳米级磷酸铁锰锂材料的方法
CN115020685A (zh) * 2022-07-26 2022-09-06 湖北亿纬动力有限公司 一种磷酸锰铁锂正极材料及其制备方法和应用

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2018006156A (ja) * 2016-07-01 2018-01-11 太平洋セメント株式会社 ポリアニオン系正極活物質及びその製造方法
CN109761210A (zh) * 2018-12-13 2019-05-17 天津力神电池股份有限公司 磷酸锰铁锂的制备方法及其包覆三元材料的方法
CN110890541A (zh) * 2019-11-21 2020-03-17 国联汽车动力电池研究院有限责任公司 一种表面改性富锂锰基正极材料的制备方法和锂离子电池
CN113659134A (zh) * 2021-07-09 2021-11-16 江苏乐能电池股份有限公司 一种使用共结晶法制备纳米级磷酸铁锰锂材料的方法
CN115020685A (zh) * 2022-07-26 2022-09-06 湖北亿纬动力有限公司 一种磷酸锰铁锂正极材料及其制备方法和应用

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